用简便方法计算下面各题
1．Ol×6.3                   2.18×3.12+6.88×2.18               4.4×25
0.25×39+0.25                0.8×5.67×12.5                     4.4×3.8+6.6×3.8﹣3.8
8.6×102                    （0.2+4）×25                        12.5×32×0.25．